Dilemmas of Science Teaching Perspectives on problems of practice Edited by John Wallace and William Louden London and New York First published 2002 by RoutledgeFalmer I t New Fetter Lane. london EC4P 4EE Simuluneously published in the USA dnd Canada by RoutledgeFalmer 29 West 35th Street. New York. NY 10001 RoulledgeFo/mer is on imprint or the T orlor & Froncis Group © 2002 John Williace and William Louden for editorial matter and selection; individual contributors their contribution Typeset in Bembo by Taylor & Francis Books ltd Printed and bound in Great Britain at the University Press. Cambridge All rights reserved. No part of this book may be reprinted or reproduced or utilised in any form or by <lny electronic. mechanical. or other means, now known or hereafter invented. including photocopying and recording, or in any information storage or retrieval system, without permission in writing from the publishers. Brilisl, library Calalaguing in Publico lion Dolo A catalogue record for this book is available from the British library library of Congress COlologing in PubliCOlion Dora Wallace, John (John William). Dilemmas of science teaching: perspectives on problems of practice/John Wallace and William louden. Includes bibliographical references and index. I. Science-Study and teaching. I. louden, William. II. Title. QIBI.w223 2002 507'. 1 '2-dc21 20010]4965 ISBN o -~ 15- 23762- ' (hbk) ISBN 0-<15-23763- 7 (pbk)Chapter 3 Laboratories Contributions by Bevan McGuiness, Wolff-Michael Roth and Penny J. Gilmer Editors' introduction The laboratory is a commonplace of science ~lIld school science. For more thall a (clltHry. the l:lboratory has been uniquely associated with the pursuit of school scicnce. The science curriculum is infused with images of students COlld\lcting rigorous laboratory-based experiments, numicking the behaviour of [c:"I1 scientists in real scientific labOTJtorics. 'Hands-oil' has beco11le a catch cry tor science CduCltioll. ptlfticuiarly over the past forty years, driving rurricuhll11 dC\TloplllCllt (and f.lcilities management) in the developed and developing \Yorlds. And yet. notwithstanding the ccntral place of the labora-tOl)' ill school scicnce. there is a growing corptlS of rcsertrch which caBs into question both its value and dlectiveness, ;md its connection to the enterprise of science (Hegarty-Hnc\. 1990; Hodson, 1993; Ln.rowitz and Tamie, 1994; Milne and Taylor. 1998; Tobin. 1990). Two 1I1;~or critiques of school science laboratories have emerged in recent times. The first critique draws attention to the mismatch between the high ideals of laboratory-based inquiry and the reality of most 'cookbook' styJe practical work. with its emphasis on skill development and confirmation of prcdctcrlliined rOllclllsioIlS (HodsOlI, 1993). The presUlllptioll that the school science lahoratory is a pbcc for gelluine inquiry is largely a myth (Hodson, 1990; Milne and Taylor, 1998). Much of what goes on under the guise of cxperimentation is routinised ;md more concerned with technique and data than discourse. Assesslllents typically reflect an image of laboratory work as a dosed rather than an opcn-ended enterprise. Genuine experimentation is rarc. ortCIl confined to extra-curricubr science activity such as science fairs. Gi\'Cn this st;lte of aff;lirs. many commentators are now calling for more ;authentic' forms of laboratory work aBd assessment, emphasising intellectual ;llId prohIcIll-suh-ing skills. a II11ICh reduced emphasis on technical skill-based bench work (Arzi. 1998) and an expanded definition of the terlll 1;lboratory to illcorpor;ltc recellt ;H\VJIlCCS in information technology, and data collection ;mel processing. Laboratories 37 A second and related critique of laboratory work centres on the aSStllllp-tioll that students can mim..ic in some way wh<lt happellS in 'real' science laboratories. Many scholars have observed that science in 'real' laboratories is conducted withill a social milieu of interpretatiOlI,justification and argumell-tation. Scientific positions are 'constituted by the researchers' paradigmatic affinities which contribute to frame a phenomenon, to defin e the operating conditions under which its observation is carried out' (Desautels and Larochelle, 1998, p. 118) and to determine how data arc to be treated (Woolgar, 1990). These positions ;'If e socially derived and argued withill particular conullunities of scholars, in accordance with sets of beliefs, rtlles and assllmptions. By contrast, school students typically act from all individual-istic perspective, believing that objects or phenomena offer up observations to the observer, that d<1ta speak for themselves, and that observations and data form the b<1sis for theory building or modific;ltioJl (Desautels and LlTochellc, 1998). Indeed, in the absence of all interpretative frame, students appear ill equipped to mimic the mature and complex p;ltterllS of social behaviour of 'real' scientists. T<lken together, these two critiques -about the ntismatch between goals and realities, and :tbout the difference between school science and 'real' science -provide a complex set of issues for teachers and others who wish to reform the school science laboratory. These issues include how to imagine J form of laboratory work which is 'authentic' in a world where students lack the social and cognitive resources to lltintic the scientific ende;wour, how to move the emphasis from an individualistic view of science towards science as a sociaJ practice, and how to shift £i'om a culture of right answers to a culture of interpretation, negotiation and justification. These issues forlll the back-drop to the story that follows. III TitratiollS, tilratiolls, Devan McGuiness recollnts his experience in teaching the technique of titration to a group of Grade 11 senior chentistry students. In doing so, he raises questions about the relevance of the activity and the type of learning taking place. The story is followed by his own commentary on thc activity and cOllllllentaries by Wolff-Michael Roth and Penny Gilmer. Titrations, titrations Bevan McGuiness Teaching senior chemistry can be a mixed blessing sometimes. There are times when you just have to slog through lengthy theoretical sections, such as